1. Field of the Invention:
The present invention relates to a cooling apparatus for a high-temperature medium by boiling and condensing refrigerant, capable of absorbing heat generated from a high-temperature medium such as a heating body of a semiconductor device or electric device, to cool the high-temperature medium.
2. Description of Related Art:
There have been known cooling apparatuses for a high-temperature medium by boiling and condensing refrigerant, for cooling heat generated from a high-temperature medium such as a heating body. Among those known cooling apparatuses, as disclosed in JP-A-56-147457, JP-U-62-151755, or JP-A-6-53376, there is a cooling apparatus capable of preventing a flooding of ascending refrigerant which has been boiled and vaporized and liquid refrigerant which has been cooled in a radiator and is returning to a refrigerant tank, within the apparatus, i.e., the flooding being a phenomenon in which both refrigerants collide with each other, to perform a heat exchanging operation efficiently.
The cooling apparatus disclosed in JP-A-56-147457 includes a refrigerant tank for containing a refrigerant to be boiled and evaporated by heat generated by a heating body, an inflow passage having a substantially uniform diameter communicating with the refrigerant tank, a radiator having a plurality of radiating passages communicating with the inflow passage, and an outflow passage through which the refrigerant condensed and liquefied in the radiator is returned to the refrigerant tank.
According to this cooling apparatus, bubbles of the refrigerant blow up and the gas-phase refrigerant flows through the inflow passage into the refrigerant passage to transfer heat.
Generally, disposing an inner fin inside the refrigerant passage in the radiator for improving the radiating performance is well known. Thus, it is considerable that the inner fin is disposed inside the refrigerant passage in the cooling apparatus disclosed in JP-A-56-147457. Also, it is considerable that a projection is provided for positioning and fixing the inner fin when the inner fin is disposed.
However, when the projection is disposed to contact a bottom surface of the refrigerant passage, the liquid refrigerant condensed in the refrigerant passage is blocked by the projection in a flow passage reaching the outflow communicating portion. That is, the refrigerant flowing in the lowest portion (bottom surface portion) of the refrigerant passage is dammed by the projection and stored in the refrigerant passage. As a result, an amount of the refrigerant used in a refrigerant circuit is reduced. Thus, the heat transmitting area in the refrigerant passage is reduced thereby deteriorating the radiating performance.
Further, in the cooing apparatus disclosed in JP-A-6-53376, when the cooling apparatus is inclined so that the condensed liquid flows in reverse, the condensed liquid cannot return to the refrigerant tank. In the cooling apparatus disclosed in JP-U-62-151755, the refrigerant passage is inclined to return the condensed liquid into the tank. However, the entire height and width of the apparatus are enlarged, i.e., the size of the apparatus is enlarged, to incline the refrigerant passage.